From patchwork Tue Sep 16 12:59:20 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 4917831 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D65929F349 for ; Tue, 16 Sep 2014 12:58:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3B662201F5 for ; Tue, 16 Sep 2014 13:00:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4528D200FF for ; Tue, 16 Sep 2014 13:00:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754053AbaIPM7l (ORCPT ); Tue, 16 Sep 2014 08:59:41 -0400 Received: from mailout3.w1.samsung.com ([210.118.77.13]:22432 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754026AbaIPM7j (ORCPT ); Tue, 16 Sep 2014 08:59:39 -0400 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NBZ007VZW830R00@mailout3.w1.samsung.com>; Tue, 16 Sep 2014 14:02:27 +0100 (BST) X-AuditID: cbfec7f5-b7f776d000003e54-97-54183438e5a0 Received: from eusync2.samsung.com ( [203.254.199.212]) by eucpsbgm2.samsung.com (EUCPMTA) with SMTP id 69.D8.15956.83438145; Tue, 16 Sep 2014 13:59:36 +0100 (BST) Received: from AMDC1943.digital.local ([106.116.151.171]) by eusync2.samsung.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPA id <0NBZ00CMUW32T2A0@eusync2.samsung.com>; Tue, 16 Sep 2014 13:59:36 +0100 (BST) From: Krzysztof Kozlowski To: Russell King , Dan Williams , Vinod Koul , linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Ulf Hansson , Grant Likely , Lars-Peter Clausen , Michal Simek , "Rafael J. Wysocki" , Len Brown , Pavel Machek , Randy Dunlap , Alan Stern , linux-doc@vger.kernel.org, linux-pm@vger.kernel.org Cc: Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz , Krzysztof Kozlowski Subject: [PATCH v5 4/4] dma: pl330: add Power Management support Date: Tue, 16 Sep 2014 14:59:20 +0200 Message-id: <1410872360-27029-5-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1410872360-27029-1-git-send-email-k.kozlowski@samsung.com> References: <1410872360-27029-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrELMWRmVeSWpSXmKPExsVy+t/xK7oWJhIhBscfilpsnLGe1WL61AuM Fqun/mW1OPBnB6PF6xeGFmeb3rBbLJk8n9Vi1pS9TBYL25awWFzeNYfN4nPvEUaL25d5LdYe uctu8e5lhMXdU0fZLN7emc5iceb0JVaLCb8vsFkcXxtu8bJvP4uDiEdLcw+bx+YVWh6L97xk 8rhzbQ+bx5I3h1g9tlxtZ/GYffcHo0ffllWMHitWf2f3+LxJzmPv598sAdxRXDYpqTmZZalF +nYJXBn7P19gLHhmUnHyxiGmBsYn2l2MnBwSAiYSD05vYoewxSQu3FvP1sXIxSEksJRR4vDu U0wQTh+TxP/pe1lBqtgEjCU2L18CViUicIRF4tm9J2AOs8BRRonpvW+ZQKqEBRwkduzfAGaz CKhKzH90nRHE5hVwl1h6qoERYp+cxMljk8Gmcgp4SFzfe40ZxBYCqrk5dQLzBEbeBYwMqxhF U0uTC4qT0nON9IoTc4tL89L1kvNzNzFC4uHrDsalx6wOMQpwMCrx8Gb8Ew8RYk0sK67MPcQo wcGsJMLroSkRIsSbklhZlVqUH19UmpNafIiRiYNTqoGxkJG9Qev925N+jWeajXyKnhjZTXzx JjGF/Uup/vS3V/MWLpXK6XteNG0Sg4T0Z/lXqtVtaw1zJMTrL084m3cqbdrMDXNn99wokHtx 48eEHZEhwlt7bG78Y/zy5+culV2XZH0j5E45Fl/+uqpHcsGBKcqbIm1PeV7/Zm8nFeThebj7 AoPTBOM+JZbijERDLeai4kQA9HRy9GUCAAA= Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds both normal PM suspend/resume support and runtime PM support to pl330 DMA engine driver. The runtime power management for pl330 DMA driver allows gating of AMBA clock (PDMA) in FSYS clock domain, when the device is not processing any requests. This is necessary to enter low power modes on Exynos SoCs (e.g. LPA on Exynos4x12 or W-AFTR on Exynos3250). Runtime PM resuming of the device may happen in atomic context (during call device_issue_pending()) so pm_runtime_irq_safe() is used. This will lead only to disabling/enabling of the clock but this is sufficient for gating the clock and for reducing energy usage. During system sleep the AMBA bus clock is also unprepared. Suggested-by: Bartlomiej Zolnierkiewicz Signed-off-by: Krzysztof Kozlowski --- drivers/dma/pl330.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 73 insertions(+), 4 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 4839bfa74a10..9c014874c33d 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "dmaengine.h" #define PL330_MAX_CHAN 8 @@ -1958,6 +1959,7 @@ static void pl330_tasklet(unsigned long data) struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data; struct dma_pl330_desc *desc, *_dt; unsigned long flags; + bool power_down = false; spin_lock_irqsave(&pch->lock, flags); @@ -1972,10 +1974,17 @@ static void pl330_tasklet(unsigned long data) /* Try to submit a req imm. next to the last completed cookie */ fill_queue(pch); - /* Make sure the PL330 Channel thread is active */ - spin_lock(&pch->thread->dmac->lock); - _start(pch->thread); - spin_unlock(&pch->thread->dmac->lock); + if (list_empty(&pch->work_list)) { + spin_lock(&pch->thread->dmac->lock); + _stop(pch->thread); + spin_unlock(&pch->thread->dmac->lock); + power_down = true; + } else { + /* Make sure the PL330 Channel thread is active */ + spin_lock(&pch->thread->dmac->lock); + _start(pch->thread); + spin_unlock(&pch->thread->dmac->lock); + } while (!list_empty(&pch->completed_list)) { dma_async_tx_callback callback; @@ -1990,6 +1999,12 @@ static void pl330_tasklet(unsigned long data) if (pch->cyclic) { desc->status = PREP; list_move_tail(&desc->node, &pch->work_list); + if (power_down) { + spin_lock(&pch->thread->dmac->lock); + _start(pch->thread); + spin_unlock(&pch->thread->dmac->lock); + power_down = false; + } } else { desc->status = FREE; list_move_tail(&desc->node, &pch->dmac->desc_pool); @@ -2004,6 +2019,10 @@ static void pl330_tasklet(unsigned long data) } } spin_unlock_irqrestore(&pch->lock, flags); + + /* If work list empty, power down */ + if (power_down) + pm_runtime_put(pch->dmac->ddma.dev); } bool pl330_filter(struct dma_chan *chan, void *param) @@ -2073,6 +2092,7 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned switch (cmd) { case DMA_TERMINATE_ALL: + pm_runtime_get_sync(pl330->ddma.dev); spin_lock_irqsave(&pch->lock, flags); spin_lock(&pl330->lock); @@ -2099,10 +2119,14 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned dma_cookie_complete(&desc->txd); } + if (!list_empty(&pch->work_list)) + pm_runtime_put(pl330->ddma.dev); + list_splice_tail_init(&pch->submitted_list, &pl330->desc_pool); list_splice_tail_init(&pch->work_list, &pl330->desc_pool); list_splice_tail_init(&pch->completed_list, &pl330->desc_pool); spin_unlock_irqrestore(&pch->lock, flags); + pm_runtime_put(pl330->ddma.dev); break; case DMA_SLAVE_CONFIG: slave_config = (struct dma_slave_config *)arg; @@ -2138,6 +2162,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan) tasklet_kill(&pch->task); + pm_runtime_get_sync(pch->dmac->ddma.dev); spin_lock_irqsave(&pch->lock, flags); pl330_release_channel(pch->thread); @@ -2147,6 +2172,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan) list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool); spin_unlock_irqrestore(&pch->lock, flags); + pm_runtime_put(pch->dmac->ddma.dev); } static enum dma_status @@ -2162,6 +2188,15 @@ static void pl330_issue_pending(struct dma_chan *chan) unsigned long flags; spin_lock_irqsave(&pch->lock, flags); + if (list_empty(&pch->work_list)) { + /* + * Warn on nothing pending. Empty submitted_list may + * break our pm_runtime usage counter as it is + * updated on work_list emptiness status. + */ + WARN_ON(list_empty(&pch->submitted_list)); + pm_runtime_get_sync(pch->dmac->ddma.dev); + } list_splice_tail_init(&pch->submitted_list, &pch->work_list); spin_unlock_irqrestore(&pch->lock, flags); @@ -2585,6 +2620,34 @@ static int pl330_dma_device_slave_caps(struct dma_chan *dchan, return 0; } +/* + * Assume that IRQ safe runtime PM is chosen in probe and amba bus driver + * will only disable/enable the clock in runtime PM suspend/resume. + */ +static int __maybe_unused pl330_suspend(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + + if (!pm_runtime_suspended(dev)) + amba_pclk_disable(pcdev); + amba_pclk_unprepare(pcdev); + + return 0; +} + +static int __maybe_unused pl330_resume(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + + amba_pclk_prepare(pcdev); + if (!pm_runtime_suspended(dev)) + return amba_pclk_enable(pcdev); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(pl330_pm, pl330_suspend, pl330_resume); + static int pl330_probe(struct amba_device *adev, const struct amba_id *id) { @@ -2738,6 +2801,9 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id) pcfg->data_buf_dep, pcfg->data_bus_width / 8, pcfg->num_chan, pcfg->num_peri, pcfg->num_events); + pm_runtime_irq_safe(&adev->dev); + pm_runtime_put_noidle(&adev->dev); + return 0; probe_err3: /* Idle the DMAC */ @@ -2764,6 +2830,8 @@ static int pl330_remove(struct amba_device *adev) struct pl330_dmac *pl330 = amba_get_drvdata(adev); struct dma_pl330_chan *pch, *_p; + pm_runtime_get_noresume(pl330->ddma.dev); + if (adev->dev.of_node) of_dma_controller_free(adev->dev.of_node); @@ -2802,6 +2870,7 @@ static struct amba_driver pl330_driver = { .drv = { .owner = THIS_MODULE, .name = "dma-pl330", + .pm = &pl330_pm, }, .id_table = pl330_ids, .probe = pl330_probe,